Improvement in methods of splitting stone



P. CRUGHAN.

Methods of Splitting Stone.

Patented July 8, 1873. -nfl No. 140,681y

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PATRICK OBOGHAN, OF OCKEYSVILLE, MARYLAND.

IMPROVEMENT IN METHODS OF SPLITTING STONE.

Specification forming part of Letters Patent No. 140,681, dated July 8, 1873; application filed May 27, 1873.

To all whom it may concern:

Be it known that I, PATRICK OROGEAN, of Gockeysville, in the county of Baltimore and State of Maryland, have invented a new and Improved Mode of Splitting Boek; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawing forining part of this specification, in which- Figure 1 is a perspective view, partly broken awa-y; and Figs. 2.and 3 are detail views.

The invention relates to methods of splitting olf blocks. from rocks in a quarry after the same have been leveled on the top and front faces, and channeled out at the ends and back.

It will first be described in connection with all that is necessary to a full understanding thereof, and then clearly pointed out in the claim.

In the drawing, a represents a rock from which is to be obtained blocks for building and other purposes; and a al two faces which have been leveled oli' at the requisite angle to each other. a2 is a cut made parallel to the face al with a suitable channelingmachine. a3 is a series of holes made in a plane parallel to theface a, and on a plane in which it is the object to split oif these blocks. The old method of doing this consisted in placing tapering side pieces, round on the outside and plane on the inside face, in each of the edge-holes a3, and then driving between them a wedge.

By driving one Wedge after the other in succession the block is expected to be rived in the proper plane but, in fact, it quite frequently happens otherwise. A line of split oblique to the desired plane is often the result. The

effect of this is to leave the top of the subjacent block with an awkward projection, which can only be removed at the expense of much labor and time. Of course these oblique splits 7 occur at slightly-different angles. After much thought and experiment on the subject I have found that the difficulty arises from the wedgepressure being exerted on the edge of the plane of split. Hence I bore the holes a3, as shown in Fig. 1 of drawing, so as to extend beyond the longitudinal median line of stone, and place the tapering side pieces B B across this line. I then provide the wedge C with a suitable length of shank, so that it can reachand be conveniently driven between the side v pieces B B. This enables me to oa'use a separation nearly or quite on the exact plane required.

I have verified this by numerous experiments in the presence of experts, who all aeknowledge the advantage and marked benefit arising from my new method of splitting off the blocks.

Having thus described my invention, what I claim as new, and desire to secure by Letters Paten t, is-

The method herein describe-d of splitting olf blocks of stone, the saine consisting in boring subjacently beyond the longitudinal middle line of the block, and placing the side pieces across said line, so as to cause the upanddown pressure of the wedge to be exerted inside and not on the edge of the rock, substantially as set forth.

PATRICK CBOGHAN.

Witnesses:

SoLoN C. KEMON, T. l). DURBIN OUEAND. 

